I wonder if they retrofitted to 200, 250 or 400w HPS. 200 and 250w would be the logical choice to match the lumens but I've heard of the same wattage HPS being used to replace MV in some cases.
I'd guess 250W since 200W HPS doesn't seem common in the new england area (maybe it's used some places). Personally, I'd prefer seeing 100W MV replaced with 100W HPS and 400W MV can go either way for me. Sure you can match the raw lumens but 50W HPS and 100W MV have the same lumens (4000) yet a new 100w MV appears like 2X brighter since HPS has such bad CRI.
Ahh, I guess 70w HPS would also be a good choice for retrofitting 100w MV since it's a bit brighter than 50w HPS. 175w can go either 100 or 150w HPS IMO. And I guess 200w could retrofit 250w MV. For 400w MV I prefer 250w HPS. I think 400w HPS is overkill unless you have a wide street where the extra lumens will help.
Even 70W HPS is dimmer than a new 100W MV. I compared both side-by-side on the street next to my grandparents' house. Both were drop lens and recently relamped. The 100W MV was a little brighter but the area under the MV was way better lit. Much easier to see under the MV light.
There aren't any 150W HPS around here (except for a couple from the late 80s) and there are no 200W HPS here so I can't compare them with 175 or 250W MV. There aren't any newly relamped 175W mercs either. Any 175W mercs left are probably about as bright as a new 100W merc.
For MV to HPS, I guess this is how I would ideally do things:
100W MV --> 100W HPS
175W MV --> 150W or 100W HPS (I would use 150W on busier roads, as a lot of busier roads here are lit with 100W HPS and i think they're dim)
250W MV --> 200W HPS
400W MV --> 310W HPS
1000W MV --> 750W HPS (or 400W HPS)
For changing MV to PSMH, this is how I'd do it:
70W PSMH <-- 100W MV
100W PSMH <-- 175W MV
150W PSMH <-- 250W MV
250W PSMH <-- 400W MV (for direct lumen replacement)
320W PSMH <-- 400W MV (where additional light is needed)
400W PSMH <-- 700W MV
750W PSMH <-- 1000W MV
For the lower wattages (up to 400W MV) the PSMH equivalents are almost exactly lumen-equivalent replacements (within like 200 lumens) But 700 and 1000W MV are a little tricky. 750W PSMH is much brighter than 1000W MV but 400W PSMH is quite a bit dimmer than a 700W MV (44000 lumens for 700W MV). But 70W PSMH is perfect for 100W MV, 100W PSMh is perfect for 175W MV, 150W PSMH is perfect for 250W MV, and 250W PSMH is perfect for 400W MV.
I guess it goes back to the raw lumens vs CRI debate again lol. I think both 70w HPS and 100w MV should have on paper around the same lumens but in reality the white light source, so MV would look brighter. Yeah, MV, MH and LED lit streets are a lot more crisp at night than HPS which always looked muddy to me lol.
150w HPS is also fairly rare in my parts, even rarer now since most residential streets are LED now. 200w HPS was common along some arterials here. Not sure how they are compared to 400w MV since I haven't had a chance to compare them side by side.
The few remaining mercs here were probably last relamped more than a decade ago so I can't really tell how they fair to HPS since all of them are probably dimmed out. I suspect they might have replaced burnt out mercs with HPS at one point.
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There aren't any 150W HPS around here (except for a couple from the late 80s) and there are no 200W HPS here so I can't compare them with 175 or 250W MV. There aren't any newly relamped 175W mercs either. Any 175W mercs left are probably about as bright as a new 100W merc.
For MV to HPS, I guess this is how I would ideally do things:
100W MV --> 100W HPS
175W MV --> 150W or 100W HPS (I would use 150W on busier roads, as a lot of busier roads here are lit with 100W HPS and i think they're dim)
250W MV --> 200W HPS
400W MV --> 310W HPS
1000W MV --> 750W HPS (or 400W HPS)
For changing MV to PSMH, this is how I'd do it:
70W PSMH <-- 100W MV
100W PSMH <-- 175W MV
150W PSMH <-- 250W MV
250W PSMH <-- 400W MV (for direct lumen replacement)
320W PSMH <-- 400W MV (where additional light is needed)
400W PSMH <-- 700W MV
750W PSMH <-- 1000W MV
For the lower wattages (up to 400W MV) the PSMH equivalents are almost exactly lumen-equivalent replacements (within like 200 lumens) But 700 and 1000W MV are a little tricky. 750W PSMH is much brighter than 1000W MV but 400W PSMH is quite a bit dimmer than a 700W MV (44000 lumens for 700W MV). But 70W PSMH is perfect for 100W MV, 100W PSMh is perfect for 175W MV, 150W PSMH is perfect for 250W MV, and 250W PSMH is perfect for 400W MV.
150w HPS is also fairly rare in my parts, even rarer now since most residential streets are LED now. 200w HPS was common along some arterials here. Not sure how they are compared to 400w MV since I haven't had a chance to compare them side by side.
The few remaining mercs here were probably last relamped more than a decade ago so I can't really tell how they fair to HPS since all of them are probably dimmed out. I suspect they might have replaced burnt out mercs with HPS at one point.